Abstract: Provided are methods for labeling transfer RNA comprising replacing the uracil component of a dihydrouridine of said transfer RNA with a fluorophore. The disclosed methods may comprise fluorescent labeling of natural tRNAs (i.e., tRNAs that have been synthesized in a cell, for example, in a bacterium, a yeast cell, or a vertebrate cell) at dihydrouridine (D) positions, or fluorescent labeling of synthetic tRNAs. In another aspect, the present invention provides methods for assessing protein synthesis in a translation system comprise providing a tRNA having a fluorophore substitution for the uracil component of a dihydrouridine in a D loop of the tRNA; introducing the labeled tRNA into the translation system; irradiating the translation system with electromagnetic radiation, thereby generating a fluorescence signal from the fluorophore; detecting the fluorescence signal; and, correlating the fluorescence signal to one or more characteristics of the protein synthesis in the translation system.

Abstract: There are provided methods for detection and measurement of stress in a cell, the method including introducing a labeled tRNA into the cell and detecting a change in subcellular localization of the labeled tRNA in the cell, based on the signal emitted from the labeled tRNA. There are further provided methods and systems for the generation of a stress index of a living cell. There are further provided methods and systems for detection of stress in a living cell, comprising detection of changes in subcellular localization of labeled tRNA in a cell, wherein the detection is performed in real time.

Abstract: There are provided methods for detection and measurement of stress in a cell, the method including introducing a labeled tRNA into the cell and detecting a change in subcellular localization of the labeled tRNA in the cell, based on the signal emitted from the labeled tRNA. There are further provided methods and systems for the generation of a stress index of a living cell. There are further provided methods and systems for detection of stress in a living cell, comprising detection of changes in subcellular localization of labeled tRNA in a cell, wherein the detection is performed in real time.

Abstract: The present invention relates to systems and methods for measuring the rate of translation of a target protein in cells, which are based on the detection of translation of one or more predetermined codon pairs during synthesis of the target protein. The detection is provided by a FRET signal emitted from labeled tRNA molecules which are juxtaposed during synthesis of the protein.

Abstract: Systems for measuring protein translation and methods for measuring overall translation activity in viable cells or subcellular compartments is disclosed. The methods identify general ribosomal activity, if desired at sub-cellular resolution, thereby providing a signal indicating the rate of any of the steps of protein synthesis selected from initiation, elongation, termination or recycling. The translation system can be used to identify translation modulators in high-throughput-screening (HTS).

Abstract: There are provided methods for detection and measurement of stress in a cell, the method including introducing a labeled tRNA into the cell and detecting a change in subcellular localization of the labeled tRNA in the cell, based on the signal emitted from the labeled tRNA. There are further provided methods and systems for the generation of a stress index of a living cell. There are further provided methods and systems for detection of stress in a living cell, comprising detection of changes in subcellular localization of labeled tRNA in a cell, wherein the detection is performed in real time.

Abstract: The present invention relates to systems and methods for measuring the rate of translation of a target protein in cells, which are based on the detection of translation of one or more predetermined codon pairs during synthesis of the target protein. The detection is provided by a FRET signal emitted from labeled tRNA molecules which are juxtaposed during synthesis of the protein.